<template>
  <div>这是根组件 - {{ count }} - <button @click="fn">++</button></div>
  <Child />
</template>

<script>
import Child from "@/components/Child";
export default {
  components: {
    Child,
  },
  data() {
    return {
      count: 10,
    };
  },
  methods: {
    fn() {
      this.count++;
    },
  },
};
</script>
